B7-33 protocol · PepGuide

Check your units. The units in this table assume 2 mg/mL, but the guide's recommended mix makes 5 mg/mL. If you mix it that way, your units will be different. Use the calculator to get the right draw for your vial.

Research-derived

5–25u

100–500 mcg · Daily

SubQ. Animal-study-derived range only, no validated human dose or safety margin.

Off

variable

No established cycle, preclinical compound.

Phase	How often	Dose	Units	Notes
Research-derived	Daily	100–500 mcg	5–25u	SubQ. Animal-study-derived range only, no validated human dose or safety margin.
Off	variable	–	–	No established cycle, preclinical compound.

Units column is labelled “Units (2 mg/mL)” on the page.

What to expect

Unknown in humans. Animal data suggest anti-fibrotic, organ-protective effects; not demonstrated in people.

How much to buy

For 4-wk @ 400 mcg/day, research-derived, not a recommendation:

~6

× 2mg vials

~2

× 10mg vials

Men & women

Relaxin analog, contraindicated in pregnancy (relaxin acts on the reproductive tract). Otherwise unisex; entirely preclinical.

Dilution calculator

Set to the guide's typical mix for B7-33. Change anything to see where to draw.

Vial size

BAC water added

Dose you want

Draw to

8u

Volume

0.08 mL

Strength

5 mg/mL

Doses per vial

5

Assumes a U-100 insulin syringe (100 units = 1 mL). Double-check against the compound's page before you draw.

Recommended mixes

Vial	Water	Strength
2 mg	0.4 mL	5 mg/mL
10 mg	2 mL	5 mg/mL

2 mg: 1 unit = 0.05 mg (50 mcg)

Storage

PowderFreeze-dried: -4°F.
MixedReconstituted: 36–46°F, up to 4 weeks.

Don't use if: Pregnancy and lactation (relaxin acts on reproductive tissue) · Hypersensitivity to the peptide · Unstable cardiovascular disease (vascular effects) without supervision

Stop if you notice

Any significant cardiovascular symptoms (dizziness, palpitations, hypotension)
Any unexpected systemic reaction
Pregnancy

Side effects

Unknown in humans. Relaxin-class effects (vasodilation, connective-tissue softening) are plausible. Human side-effect profile undefined.

Drug interactions

Antihypertensives / vasodilators: possible additive vasodilation. Otherwise uncharacterized in humans.

Labs

If targeting organ fibrosis: relevant organ panels (liver, renal, cardiac markers). Blood pressure monitoring.

What these labs mean →

Warnings

No human safety, efficacy, or dosing data; entirely preclinical. Relaxin signaling has broad vascular and connective-tissue effects. Not an approved drug; quality varies, request a COA.

Patient education

Promising anti-fibrotic mechanism, but zero human data; treat as experimental. Not for use in pregnancy. Source quality matters, request a COA. If used for an organ-fibrosis goal, do so only with medical monitoring.

These apply on top of the universal safety rules.

Pairs well with

Theoretical anti-fibrotic stacks (BPC-157, TB-500)

unproven; no human data to guide combinations

BPC-157 TB-500 (Thymosin Beta-4)

Avoid with

Pregnancy

relaxin affects the reproductive tract

Significant cardiovascular disease without supervision

Use without renal/hepatic monitoring if targeting fibrosis

Can B7-33 + BPC-157 share a syringe?

Can share a syringe. Both are water-based. Combine them if you dose on the same schedule and site.

What it does

B7-33 is a single-chain analog of human relaxin-2 that selectively activates the RXFP1 receptor. In animal models it reduces fibrosis markers and tissue scarring (liver, kidney, cardiac) comparably to native relaxin, with organ-protective, anti-fibrotic effects. All evidence is preclinical.

Caution

Caution: B7-33’s entire evidence base is animal data. There is no clinically validated protocol, no approved human route, and no established safety margin. Doses here are research-derived and included for completeness only. Relaxin signaling affects the vasculature and connective tissue broadly.

References

PubMed researchdosing peptidedosages

From the guide, page 19.